遍历,如果发现与第一位相同的元素,向后检查是否一致,不一致弹出,如果遍历完成仍未发现,返回-1.
int strStr(string haystack, string needle) {
int s2 = needle.size(),s1 = haystack.size() - s2;
if(s2 == 0) return 0;
if(s1 < 0) return -1;
bool test;
for(int r = 0;r <= s1;++r){
if(haystack[r] == needle.front()) test = true;
else test = false;
for(int n = 0;n < s2 && test;++n){
if(haystack[r + n] != needle[n])
test = false;
}
if(test)
return r;
}
return -1;
}